Surveillance is commonly understood as an activity that law enforcement agencies engage in to gather information about criminals and other wrong-doers. When many people think of surveillance, images of espionage and secret policing activities come to mind. Following the 11 September 2001 attacks on Washington and New York, and the 7 July 2005 bus and train bombings in London, surveillance has also increasingly been understood in terms of border security provisions and anti-terrorism measures. Border security and formal law enforcement operations – overt and covert – are important forms of contemporary surveillance. But when surveillance is represented primarily if not exclusively as a security issue, the term fosters images of a relatively small and powerful group of people who have the means and the desire to monitor the masses (see also Haggerty's forward to this volume).